Thread-cutter for sewing-machines.



F. ZALESKI.

THREAD CUTTER FOR SEWING MACHINES. APPLICATION FILED NOV. 20, 19m.

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FRANK TzALEsKr, or soMEnvrLLE, nassacnusnrrs, assrenon' TO THE REESE BUTTON HOLE MAcHmEooMPANY, or Bos'ron, massacnusn'r'rs, A conronn- TION 0F MAINE.

THREAD-CUTTER FOR SEWING-MACHINES.

amie.

Specification of Letters Patent.

To all whom itmay concern:

Be it known that I, FRANK ZALEsKr, a subject of the Emperor of Germany, residing at Somerville, county of Middlesex, State of Massachusetts, have invented an Improvement in Thread-Cutters for Sewing-Machines, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to sewin machines and has for its object to provi e a novel thread-cutting attachment by which the needle-thread is automatically severed at. the

end of a predetermined stitching operation. In the preferred embodiment, of my invention this thread-cuttin device has associated therewith a threa clamp which automatically engages and holds the severed endof the needle thread until the stitching operation is begun again thereby relieving the operator of the necessity of holding the end of "the needle thread during the formation of the first stitch.

While my invention may be applied to various types of sewing machines, it is peculiarly applicable to sewing machines of that type embodying a cloth-clamping mechanism in which the cloth to be sewed is clamped, a stitch frame carrying'the stitchforming mechanism, and means for causing a relative movement between the clothclamping mechanism and the stitch frame during the sewing operation. Examples of sewing machines of this type may be found in the following United States Letters Patent: 'NO. 494,280, March 28, 1893; N0.

655,637, August 7, 1900; No. 1,019,677, March 5, 1912. These patents illustrate and describe buttonhole sewing machines in which the stitch frame carrying the upper ard. under thread mechanism is movably mounted on the main frame which carries the cloth-clamping mechanism, and the construction is such that when the machine is started the buttonhole is first cut and then the stitch frame moves rearwardly to bring the upper and under thread mechanism into position to concatenate the edge stitches around the cut buttonhole, and after this operation has been completed, the stitching mechanism is brought to rest with the needle raised and the stitch frame is moved forwardly again into its initial position, dur

ing which time the work-clamping mechamsm 1s released to unclamp the work.

Patented se t. a, rare.

In the preferred embodiment of my in- ,r vention the thread-cutting device is associated with the thread clamp and is so arranged that when the stitch frame moves forwardly after the buttonhole has been stitched, the thread leading from the raised needle to the work will be carried against the thread cutter and thereby severed. As I sociated with the thread cutter is a clamp to grip the severed end of the needle thread, which grip holds the thread until the stitching operation is begun on the next buttonhole. With this invention, therefore, the operator is relieved of the duty of cutting the thread at the end of the stitching operation and of holding the severed end of the thread while the stitching operation is started on the next buttonhole.

In order to give an understanding of the invention, 1 have illustrated a portlon of a buttonhole sewing machine of the Reece type, such as illustrated in the above-mentioned patents and to which my invention is applied.

Figure 1 is a side view of a portion of the stitch frame and clamp frame of a machine of the above type showing my improvements; Fig. 2 is a plan view of the thread cutter and clamp; Fig. 3 is a side view thereof; Fig. 4 is'an underside view; 5 is an enlarged section on the line wa;, Fig. 2. a

In the sewing machine herein illustrated 1 designates a portion of the so-called stitch frame Which carries the upper and under thread mechanism, the former only being illustrated herein and being constituted by.

the usual needle 2 which is supported in a reciprocating needle bar 3, and 4: designates a part of the base frame or clamp frame to which the work is clamped. The clamp frame and the stitch frame 1 are given a movement relative to each other during the stitching operation, and in the illustrated embodiment of the invention this relative movement is secured by moving the stitch frame, such movement being derived from a feed cam 26 having a groove in its upper surface in which is received a projection 27 extending from the stitch frame, this being a common well-known construction for moving the stitch frame and clamp frame relathe stitching on the buttonhole begins.

tive to each other. In the construction herein shown the work clamp comprises two clamping members 5 which are carried by arms 6 pivotally mounted at 7 to the clamp frame, these clamping members engaging the work either side of the buttonhole being stitched and being movable toward and from the base frame 4 to clamp or release the work. When the sewing machine is at rest the parts occupy the relative position shown in Fig. 1, and when the machine is first started in operation the Work clamps 5 are automatically carried into position to clamp the work and the buttonhole is cut, and then the stitch frame 1 moves relative to the clamp frame 4 to bring the needle into the dotted line position Fig. 1, at which tuipe s the stitching proceeds the edge stitches are formed down one side of the buttonhole, around the end of the buttonhole, and back on the other side of the buttonhole, and when the stitching on the buttonhole is completed the stitching mechanism is brought ,to rest with the needle 2 raised, as shown in dotted lines Fig. 1. At this time the stitch frame is moved again relatively to the clamp frame to bring the parts into the relative position shown in full lines Fig. 1.

The mechanism as above briefly described is part of the well-known Reece buttonhole sewing machine, and as itsconstruction and operation is familiar to those skilled in the art, further description is not necessary. In

. the embodiment of the invention herein illustrated I have provided the work clamp 5 with a thread-cutting attachment arranged so that when the needle moves from the dotted line position Fig. 1 to the full line position, the portion 8 of the needle thread 9 leading to the work is severed, thus relieving the operator of the necessity of cutting the thread by a manual operation. The thread cutter herein illustrated comprises a cutting blade 10 which is stationarily secured to one of the clamps 5 and which is situated'to engage and sever the thread as the needle moves forward from its dotted to its full line position at the end of the stitc'hing operation. This cutter 10 may be supported on the work clamp in any suitable way. As herein shown I provide a holder 11 therefor which is provided with means for attachment to one of the work clamps 5. The holder herein shown and which I find to be a practical one comprises a body portion 12,

with which the cutting edge 13 of the knife cooperates, and a laterally-extending holding arm 11 shaped to overlie and be secured to the clamp 5, said arm being herein shown as provided with an aperture 15 through which an attaching screw 16 may be passed to secure the device to one of the clamps 5. The body 12 is also provided with a laterallyextending knife-supporting projection 17 to which the cutting knife 10 is secured by means of a screw 18. The cutting edge 13 of the knife is rounded, as at 19, and the arm 14 is shown as having the curved threadguiding projection 20 which forms with the cutting edge of the knife a divergent throat into which the portion 8 of the needle thread is drawn during the movement of the stitch frame which carries the needle bar and needle from the dotted to the full line position Fig. 1. As the portion 8 of the needle thread enters the throat, it is drawn against the cutting edge 13 of the cutting blade 10 and is held against the edge by the body portion 12 of the thread cutter. The thread will thus be severed automatically as the needle moves from the dotted to the full line position. In sewing machines of this type it is necessary to hold the end of the needle thread at the beginning of the stitching operation in order that the first stitch may be properly formed, for unless the end of the thread is held, said end is likely to be drawn through the fabric during the formation of the first stitch, thus destroying the loop of needle thread with which the under thread is to be concatenated. I have, therefore, associated with my thread cutter a thread-gripping device which grips and holds the severed end of the needle thread until the first stitches are formed on the next buttonhole. This threadgripping device is shown in the form of a clamping blade 23 which is preferably made of resilient material and overlies the body portion 12 of the thread cutter directly above the cutting knife 10. This thread-gripping member is shown as secured at one end to the body 12 by means of a screw 24, the other end thereof being flared outwardly to form with the portion 20 a divergent mouth into which the thread is drawn during the movement of the needle from the dotted to the full line position Fig. 1. The gripping pressure of the member 23 on the thread is regulated by a. set-screw 25 which is screw-threaded through the body portion 12 and the pointed end of which engages the member 23.

From the above it will be seen that at the end of the stitching operation, the end 8 of needle thread will be automatically carried into the divergent mouth between the portion 20 and the thread clamp 23 and cutter 10, and said thread will be severed, and the severed end will be held and gripped by the member 23 until the stitching operation is commenced on the next succeeding buttonhole. The operator is, therefore, relieved entirely from the duty of either cutting the thread at the end of one stitching operation or of holding the thread at the beginning of the next stitching operation.

IVhile I have illustrated herein a selected embodiment of my invention I do not wish to be limited to the constructional features shown.

women I claim:

1. In a sewing machine, the combination with a stitch frame carrying a reciprocating needle, of a clamp frame, work-clamping means on the clamp frame, said frames hav-' ing a movement relative to each other after the needle has been brought to rest upon the the completion of a predetermined stitching operation, and a needle-thread-cutting device secured to the work-clamping means and so situated that the needle thread is brought into position tobe cut thereby by such relative movement of the frames.

2. In a sewing machine, the combination with a stitch frame carrying a reciprocating needle, of work-clamping means, said stitch frame and work-clamping means having a movement relative to each other in a direction at right angles to the direction of movement of the needle after theneedle has been brought to rest upon the completion of a predetermined stitching operation, a needlethread-cutting device secured to the workclampin means and situated so that the needle thread is carried into position to be cut thereby by such relative movement, and a thread clamp associated with the cutting device and operating to clamp the severed end of the needle thread.

3. In a buttonhole sewing machine, the combination with stitchforming mecha nism, of work-holding means, said stitchforming mechanism and work-holding.

means having a movement relative to each other subsequent to the completion of the stitching operation on the buttonhole to bring the parts from stitching po sition to buttonhole-cutting position, and a needle-thread-cutting device secured to the work-holding means and so situated that said relative movement brings the needle thread into position to be cut thereby.

4. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of work-holding means, said stitchforming mechanism and work-holding means having a movement relative to each other subsequent to the completion of the stitching operation on the buttonhole to bring the parts from stitching position to buttonhole-cutting position, a needle-threadcutting device secured to the work-holding means and so situated that said relative movement brings the needle thread into position to be cut thereby, and means to clamp the severed end of the needle thread.

In a sewing machine, the combination with a stitch frame carrying a reciprocating needle, of a clamp frame, awork clamp movably mounted on the clamp frame, said frames having a movement relative to each other in a direction at right angles to the direction of movement of the needle at the end of a predetermined stitching'operation, and a combined needle-thread-clamping and needle-thread-cutting device secured to the work clamp and situated so that the needle thread will be drawn into the clamping device and against the cutting device by such relative movement of the frames.

6. In a sewing machine, the combination with a stitch frame carrying a reciprocating needle, of a clamp frame, a Work clamp movably mounted on the clamp frame, said frames having a movement relative to each other after the needle has been brought to rest upon the completion of a predetermined stitching operation, a thread-clamping de-' vice secured to the work clamp and comprising a. body member and resilient clamping blade situated so that the needle thread will one of said relatively-movable elements 'during the stitching and for giving it an additional movement after the completion of the buttonhole, and a device carried by one of said elements for cutting and holding the thread between the work and needle, operated by'reason of said additional movement after the stitching is completed.

8. A buttonhole or analogous stitching machine including in combination a stitch frame and a work clamp constituting relatively-movable elements, a needle and needle-actuating mechanism supported by the stitch frame, means for shifting one of said relatively-movable elements at the completion of a seam, and a device operated by said shifting for cutting and holding the thread between the work and needle, said device consisting of a passive cutter and holder mounted stationarily on said work clamp, having a cutting bladebelow, and above the blade a thread-clamping device adapted to receive and retain the thread by the act of enterin the thread thereinto so that upon said shifting of one of the relatively-movable elements the thread enters the clamp and is cut between the clamp and the work.

9. A buttonhole or analogous stitching machine including in combination a stitch frame and a work clamp constituting relatively-movable elements, a needle and needle-actuating mechanism supported by said stitch frame, automatic means for shifting one of said relatively-movable elements at the completion of a seam, and a thread cutter and clamp mounted stationarily on one of said elements in proper position so as. to be operated by said shifting tively movable for cutting and holding the thread between the work and the needle.

10. A buttonhole or analogous stitching machine including in combination a stitch frame and work clamp constituting relatively-movable elements, a needle and needle-actuating mechanism supported by said stitch frame, automatic meansfor shifting one of said relatively-movable elements at the completion of a seam, and a device operated by said shifting for cutting and holdingthe thread between the work and needle.

11. A buttonhole or analogous stitching machine including in combination a stitch frame and a work clamp constituting relaelements, a needle and needle-actuating mechanism supported by said stitch frame, automatic means for shifting one of said relatively-movable elements at the completion of a seam, and a device opthread between the work and the needle.

12. A buttonhole or analogous stitching machine including in combination a stitch frame and a work clamp constituting relatively-movable elements, a needle and needle-actuating mechanism supported by said stitch frame, automatic means for shifting oneof said relatively-mm'able elements at the completion of a seam, and a cutter mounted stationarily on one of said elements in position to cut the thread between the work and needle upon such shifting at the completion of a seam:

13. A' buttonhole or analogous stitching machine including in combination a stitch frame and a work clamp constituting relatively-movable elements, a needle and needle-actuating mechanism supported by said stitch frame, automatic means for shifting one of said relatively-movable elements at the completion of a seam, a cutter mounted stationarily on one of said elements in position to cut the thread between the work and needle upon such shifting at the completion of a seam, and means for holding the thread between the needle and cutting point after such cutting. erated by said shifting for cutting the In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

FRANK ZALESKI.

Witnesses:

F. A. SHEA, LOUIS C. SMITH. 

